Bailya parva is a species of sea snail, a marine gastropod mollusc in the family Pisaniidae.

Sculpture presents 10–12 axial ribs crossed by spiral lines, with beads forming at the intersections.

(Original description) The shell is elongated and subfusiform, with a dingy white spire marked by irregular pale brown stains.

The surface is covered with numerous unequal, elevated spiral lines that continue over the ribs, with the anterior ones being larger and granose.

The siphonal canal is short, wide, and slightly recurved, with a faint umbilical indentation.